Key Performance Indicators (KPI)

A Key Performance Indicator is a measurable value that demonstrates how effectively a company is achieving key business objectives. Organizations use KPIs at multiple levels to evaluate their success at reaching targets.

What is a Key Performance Indicator (KPI)?
Advanced Performance Institute
Unleashing the Power of a UX KPI
UIE
10 Essential Usability Metrics
Measuring U
A big list of UX KPIs and Metrics
CX Partners